[In the second part of his three-part series, PhD researcher and game designer Lucas Blair continues to present underpinnings in contemporary research which will help formulate best practices for designing in-game achievements. You can read part 1 here.]

Now, to recap. As I wrote in the original piece, there is an established body of scientific study covering a wide range of topics, which should guide the design of achievements. In this article series, I will be sharing a taxonomy of achievement design features created by deconstructing how achievements are currently used in games.

The goal of this exercise is to distill mechanisms of action out of achievement designs, which have been shown by research to affect performance, motivation, and attitudes.

This taxonomy, although intended to be comprehensive, is likely to be subject to debate and future revisions. For the time being however, I think it is a good jumping off point for a discussion that must be had if we are to ever effectively harness the potential of achievements.

Now, onward to the new content. In part two I will be covering the following concepts:

Expected vs. Unexpected Achievements

When Achievement Notification Occurs

Achievement Permanence

Who Can See Earned Achievements?

Expected vs. Unexpected Achievements

When a player earns an achievement, the notification they receive can come as a total surprise or as the finish line they were striving for. The expectation that a player has when starting a game stems from the design decision to let them know what they can achieve. Players either know what achievements can be earned before they play a game, or they come upon them unexpectedly during play. Expected and unexpected achievements have different effects on players and can both be utilized to improve player experience.

Expected achievements allow players to set goals for themselves before they begin. There are four well-established benefits to having players set goals for themselves. First, goals will allow the player to have objectives and allocate their resources to complete them. This could mean brushing up on certain skills, setting aside extra time, or asking a friend for help. Second, having a goal increases the amount of effort someone is willing to put into something. For game makers this will directly translate into more play time.

As someone who spent many hours pursuing the "Salty" meta-achievement in World of Warcraft -- in which a player must earn all fishing achievements -- I can personally attest to what time-sinks they can be.

Third, players who have goals are much more likely to not give up when facing a difficult task in a game, as compared to players without such goals who quit playing once the going gets too tough. Fourth, players who establish goals for themselves will acquire new knowledge and skills in order to meet those goals. This is also important to game makers, because those players who obtain new skills will in turn want to play your game more.

In addition to the benefits of goal-setting, expected achievements also allow players to create a schema, or a mental model, of gameplay before they begin. Players then refer to this schema in order to make sense of how the game is structured, and what actions they need to do in order to succeed. If a player purchases a new game and looks over all the achievements they can earn, they will develop a better understanding of the game itself. In fact, schema creation is often similarly used in training programs to help increase user performance.

On the other end of the spectrum are unexpected achievements. Unexpected achievements are relatively uncommon in video games, but can also have potential benefits to players. One such perk would be encouraging experimental play.

An extreme example of this strategy can be seen in the game Achievement Unlocked, in which players can earn quirky achievements for almost everything they do. Although the developers intended it to be a jab at the overuse of game achievements, AchievementUnlocked effectively illustrates the metagame that can be created through convincing players to run and jump around the screen randomly in hopes of earning all the mystery achievements.

Best Practice: Primarilyuse expected achievements so players can establish goals for themselves and create a schema of the game.Make sure achievement descriptions accurately reflect what needs to be done by the player and why it is important. Unexpected achievements can be used sparingly to encourage creative play.